The apparent acoustic length of the mouthpiece‐leaderpipe combination increases with frequency through the normal playing frequency range. For example, the apparent length may increase from 23 cm at 165 Hz to 35 cm at 1100 Hz. At higher frequencies it declines. Theory indicates that, at frequencies low enough for losses to be neglected, the apparent acoustic length,l, should be related to the total internal volume of the mouthpiece‐leaderpipe combination,V, the cross‐sectional area of the main cylindrical tubing to which the leaderpipe is attached,S, the resonances and antiresonances of the mouthpiece‐leaderpipe combination, Ω, and Ψn, by the equation:ctn(ωlc) = ScVΩ1[(Ω12−ω)Ψ12(Ω22−ω2)Ψ22(Ω32−ω2)Ψ32(Ω42−ω2)…ωΩ1(Ψ12−ω2)Ω22(Ψ22−ω2)Ω32(Ψ32−ω2)Ω42…].Experiments show that the tuning behavior of the mouthpiece‐leaderpipe combination can be quantitatively predicted with this equation in the frequency range from zero to 1000 Hz.